In the field of numerically controlled industrial machinery such as machine tools and robots, generally, movable structures such as a tool rest, a spindle head, a robot arm and the like can be operated by manual operations, such as jog feed and pulse feed, as well as by an automatic operation.
Further, operation keys for jog feed and a pulse handle for pulse feed are usually disposed on an operation panel, and operation signals input from the operation keys and the pulse handle are to be transmitted to a numerical controller.
When a movable structure is operated by a manual operation, the operator might perform an operation different from his intended operation due to misrecognition, for example, selecting a wrong axis of movement of a robot arm or moving the movable structure in a wrong direction. This is a so-called artificial error, and performing such a wrong operation might possibly cause a serious accident such that the movable structure operated collides with another structure.
Therefore, in order to prevent such a wrong operation, a display apparatus is proposed in Japanese Unexamined Patent Application Publication No. H7-295625 (“JP '625”). This display apparatus has a display device (CRT monitor) on which a graphics image is displayed, and a display controller which displays, on a screen of the display device, an image representing the contents of a jog mode executed by a robot controller along with an image representing a robot.
In this display apparatus, for example, 1) when the robot controller executes “tool feed mode”, the display controller displays on the display device an image of each axis of the tool coordinate system superposed on a graphics image representing the vicinity of a robot arm end and a hand, and 2) when the robot controller executes “robot coordinate system feed mode”, the display controller displays on the display device an image of each axis of the base coordinate system superposed on an image of the entire robot including the robot base. Further, 3) when the robot controller executes “user coordinate system feed mode”, the display controller displays on the display device an image of each axis of the user coordinate system superposed on an image of the entire robot, and 4) when the robot controller executes “each axis feed mode”, the display controller displays on the display device an image for indicating the position and direction of movement of each axis superposed on an image of the entire robot.
Further, the display controller is configured to be capable of highlighting the coordinate axis corresponding to the jog feed direction; for example, causing the corresponding coordinate axis to blink or changing the display color of the corresponding coordinate axis.
Thus, according to this conventional display apparatus, because the operator can easily recognize the jog mode in the form of an image before or during execution of jog feed, it is prevented that jog feed is started or continued in a state where the jog mode is wrongly recognized. Further, because the direction in which jog feed can be executed or the direction in which jog feed is being executed is recognized in the form of an image, it is possible to execute jog feed without a feeling of uneasiness and it is possible to improve the efficiency of a teaching operation using jog feed. Furthermore, highlighting the in-execution jog feed direction in the graphics display makes it possible to cause the operator to recognize the jog feed direction more definitely.